The communication has been very slow, too slow to be able to work
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Please set your Ewon and eCatcher to TCP mode instead of UDP.
Unfortunately, if you are using a 4G connection, the issue is caused by your mobile provider and the way Rockwell communication works. Rockwell PLCs use very small data packets due to their request/response model:
A PC, HMI, SCADA, or custom application sends a request
It waits for the PLC to respond
Then it sends the next request
This is the standard communication pattern when reading or writing tags over EtherNet/IP.
However, many SIM card providers do not like to transmit very small packets. They wait for more data to accumulate before sending anything. But because Rockwell’s protocol only sends small, isolated packets, no additional data arrives — so the provider keeps waiting. Meanwhile, the software is stuck at step 2 (waiting for the response).
After a timeout, since no more data arrives, the provider finally sends the small packet. This timeout is what causes the significant increase in communication delays.
Unfortunately, since the issue comes from the mobile provider’s handling of small packets, there is nothing we can do on our side to improve the link — except switching to TCP mode, which handles this situation much better.